Improvement in blackboard attachments



J.- W. THOMPSON. Blaqkboard Attachment.

No. 206,201.; 'P-atented Ju Iy 23, 1878.

ILPETERB. PHOTO-LITHOGRAFHER, WASHINGTON. D Q

UNITED STATES PATENT OFFICE.

JOHN TV. THOMPSON, OF GREENFIELD, MASSACHUSETTS.

IMPROVEMENT IN BLACKBOARD ATTACHMENTS.

Specification forming part of Letters Patent No. 206,201, dated July 23, 1878; application filed December 21, 1877.

To all whom it may concern:

Be it known that I, JOHN W. THOMPSON, of Greenfield, in the county of Franklin and Commonwealth of Massachusetts, have invented a new and useful Improvement in Trays for School-Blackboards, of which the following is a specification:

Blackboards for educational purposes have within the past few years become indispensable, and various inventions have been made for their improvement and for their convenient use with the necessary appliances.

My invention is for an improvement in the tray for holding the chalk, crayons, rubbers, 850., and for catching the pulverized chalk and dust falling from the board.

Heretofore it has been common to make at the bottom of the blackboard a narrow tray or shelf with a protecting ledge of sufficient depth and width to hold the rubbers, the crayons, and the chalk used upon the board, and to receive the chalk-dust, which in use drops down in considerable quantities, and is often 'quite a nuisance, by covering the crayons and rubbers, and by being often blown accidentally or intentionally into the room.

The object of my invention is to provide a tray which shall conveniently hold the crayons, rubbers, &c., and permit the chalk-dust to sift through into a receptacle below, where it is retained secure from accident till intentionally emptied.

The invention consists in providing the tray, extending its whole length and breadth, with a screen of wire-gauze suitably secured on the sides, and supported by slight bars D running across it. Upon this screen rest the crayons and rubbers, confined by the sides of the tray, while the chalk-dust drops through into the bottom of the tray, and the crayons and rubbers are thus kept clean.

Another great advantage is that the rubbers can -be instantly and tidily cleaned by merely drawing them along the screen.

The screen can be made of a slight frame forming the tray, or (which perhaps would be the more convenient way for boards already in use) the frame or tray holding the screen rising above the wire-gauze enough to protect the crayons and rubbers from falling, and dropping enough below it to allow for the accumulation of chalk-dust, might be attached by hinges or otherwise to the edge of the tray already in use, being constructed so as to take out or to turn over to remove the chalk-dust.

It will be at once perceived that by this contrivance the dust cannot accidentally or intentionally be blown about the room, and only removed as occasion may require.

In the accompanying drawings, A represents the blackboard; B, the tray for holding the chalk, crayons, and rubbers, and to receive the dust falling down the face of the board G, the screen forming the cover of the tray supporting the crayons and rubbers, and through which the dust falls.

The tray Bis to be made wide enough to conveniently hold the rubbers and crayons, extending the whole length of the board, a part of which is the wire screen 0, holding the rubbers, and allowing the passage through it of the falling dust.

I do not confine myself to any particular mode of securing the screen, so that the dust may readily be removed, but have found in practice that one of the two methods indicated above is preferable.

I am aware that blackboards provided with trays covered with wire gauze or netting have been made and used, and, in view of the patent granted by the United States to H. B. Marshall, No. 169,649, November 9, 1875, do not claim, broadly, this device.

That I do claim is-- In combination with the blackboard A, the tray B and screen 0, when said screen is socurely fastened to its frame and supported by strips or stays D, as and for the purpose set forth.

JOHN \V. THOMPSON.

\Vitnesses:

Jnnns S. GRINNELL, FRANoIs M. THOMPSON. 

